Process for regulating setting time of hydraulic cement

ABSTRACT

The present invention is an improved one of the U.S. Patent 3,782,992 and relates to a process for regulating setting time of hydraulic cement which comprises clinker containing 5-60 percent by weight of 11CaO.7Al2O3.CaX2, more than 5 percent by weight of 3CaO.SiO2, and further 2CaO.SiO2 solid solution and 4CaO.Al2C3.Fe2O3; anhydrite with or without hemihydrate; at least one selected from the group consisting of sugars, sodium hydrogen carbonate, water-soluble phosphates, carboxylic acids, silicofluorides, sodium silicates, ligninsulfonate, sulfuric esters of higher alcohol and alkylsulfonates, whereby the anhydrite is contained in an amount that Al2O3/SO3 weight ratio of Al2O3 in the clinker and SO3 in the anhydrite is 0.7 - 1.8 and hemihydrate is contained less than 5 percent by weight based on SO3.

[451 Feb. 18, 1975 1 1 PROCESS FOR REGULATING SETTING TIME 01" HYDRAULICCEMENT [75] Inventors: Hiroshl Uchikawa, Funabashi;

Shunichiro Uchida, Chiba, both of Japan [73] Assignee: Onoda CementCompany, Limited,

Onodo-shi, Yamaguchi,.lapan [22] Filed: July 6, 1973 [21] App]. No.:377,111

Related U.S. Application Data [62] Division of Ser. No. 253,352, May 15,1972.

OTHER PUBLICATIONS Lea & Desch, The Chemistry of Cement & Concrete,

Ed. Arnold Pub., London, 1956, pp. 466.

Primary Examiner-Delbert E. Gantz Assistant Examiner-James W. HellwegeAttorney, Agent, or Firm-Oblon, Fisher. Spivak, McClelland & Maier [57]ABSTRACT The present invention is an improved one of the U.S. Patent3,782,992 and relates to a process for regulating setting time ofhydraulic cement which comprises clinker containing 5-60 percent byweight of l lCaO.- 7Al O;,.CaX more than 5 percent by weight of 3CaOLSiOand further 2CaO.SiO solid solution and 4CaO.Al,C .Fe O anhydrite withor without hemihydrate; at least one selected from the group consistingof sugars, sodium hydrogen carbonate, water-soluble phosphates,carboxylic acids. silicofluorides, sodium silicates, ligninsulfonate,sulfuric esters of higher alcohol and alkylsulfonates, whereby theanhydrite is contained in an amount that Al O /SO weight ratio of A1 0in the clinker and 80;, in the anhydrite is 0.7 -1.8 and hemihydrate iscontained less than 5 percent by weight based on $0 9 Claims, 4 DrawingFigures FIG. 2

Difference between Initial and Fmal Seflmg T|me(mm) Added Amount ofGoldctosehm 10 40 E 30 v 2 i: t .2 20 X IO 0T5 L'o |.'5 20 Added Amomtof Golociosa(x|0"%) PATENTED FEB I 81975 SHEET 3 OF 4 FIG. 3

zaduys 4 3 m m m A I 03 in CI inker 50 i! Anhydrif'e PATENTED FEB 81975SHEET u 0F 4 FIG.4

28dcys PROCESS FOR REGULATING SETTING TIME OF HYDRAULIC CEMENT This is adivision, of application Ser. No. 253,352 filed May 15, i972.

The present invention relates to a process for suitably regulatingsetting time of hydraulic cement which has high strength at the initialand later stages. The initial and later stages means less than 6 hrs andmore than 3 days. respectively. in the present invention.

When the mixed raw materials comprising calcareous, silicious andaluminous material as well as a small amount of halide such as calciumfluoride. calcium chloride, etc. are sintered. the initialcrystallization region of calcium aluminate (3CaO.Al- O is extremelynarrowed and the clinker obtained will not contain calcium aluminate,and contains 1lCaO.7Al O .CaX (X represents a halogen atom) as a stablephase, and thus the clinker containing I1CaO.7Al O .CaX as a stablephase. as well as 3CaO.SiO-,, 2CaO.SiO 4CaO.Al O Fe O etc. is obtained.

I1CaO.7Al O;,.CaX component has a high hydration activity and a greaterhardenability, so it is effective that hemihydrate (or hemihydrategypsum) is added to the clinker containing 1lCaO.7Al O .CaX

HO. 1 shows the relation between the compressive strength of cementmortar comprising the clinker and the added amount ofgalactose whenanhydrite is added or is not added.

HO. 2 shows the relation between a difference be tween the initial andthe final setting time or the setting time of the cement mortar as usedin FIG. I and the added amount of galactose.

FIG. 3 shows the relation between the compressive strength of cementmortar comprising the clinker and Al O /SO ratio ofAl O;, in the clinkerand SO in anhydrite.

FIG. 4 shows the relation between the compressive strength of cementmortar comprising the clinker and the added amount of sodiumsilicofluoride (based on F).

Bauxite. quick lime, and copper slag as well as fluorite were ground.respectively. and mixed so as to obtain clinker having a composition asshown in Table l. The resulting mixture was shaped and sintered at l320-]330C. The thus obtained clinker was ground to powder having Blainespecific surface area of 3,700 cm /g. The composition of the clinkeranalized by X ray diffraction analysis are shown in Table I.

Table 1 Chemical composition (71) Mineral composition ('71) siocomponent for retarding the setting time thereof and also insolubleanhydrite (or insoluble anhydrite gypsum) is added to the clinkercontaining llCaO.7Al- O .CaX for developing strength in the initial andthe later stages. However, as disclosed by US. Pat. No. 3.782.992, wehave found that if at least one of sulfates. nitrates and chlorides ofpotassium. sodium. magnesium. calcium. aluminium and ammonium (exceptingCaSO,.l/2H O), is added to the clinker as a substitute of hemihydrate.setting time of cement thus obtained is retarded and the hardened matterhas excellent strength, and that if the above-mentioned additive isadded to the clinker with anhydrite and hemihydrate, setting time ofcement thus obtained is retarded and the cement have good workabilityand more excellent strength development property at the early and thelater stages than that of the former cement. The early stage meansbetween 6 hrs and 3 days in the present invention.

An object ofthe present invention is to provide a process for regulatingsetting time of hydraulic cement comprising IlCaO.7Al O .CaX by using anadditive other than the above-mentioned additives.

Another object of the present invention is to provide a process forpreparing cement which has good workability and high initial strengthand a hardened material thereof has ,high strength for a long period oftime.

We found that in addition to the abovementioned additive. sodiumhydrogen carbonate. water-soluble phosphates. silicofluorides. sodiumsilicates. sugars. c rboxylic acids. ligninsulfgnates, sulfuric estersof hmr alkylsulfonates is effective.

The present invention can be more fully understood from the followingdetailed description when taken in conjunction with reference to theaccompanying drawings, in which:

Natural gypsum having a composition of Table 2 was used to produce thefollowing products.

Hemihydrate: The natural gypsum of Table 2 was kept at 160C for 3 hoursand was cooled and ground to powder having a Blaine specific surfacearea of 5,000 cm lg.

Insoluble anhydrite: The natural gypsum of Table 2 was kept at 800C inan electric furnate for 1 hour. and was cooled and ground to powderhaving a Blaine specific surface area of 4,200 cm /g.

These gypsum products were used after the chemical form thereof wasidentified by thermal analysis such as diffrential thermal analysis orthermobalance analysis.

In order to determine the relation between the amount of galactose to beused and the setting time or the compressive strength after setting ofcement mortar, the setting time and the compressive strength of mortarwere determined with respect to cement in which galactose was mixedalone and in which anhy drite was mixed in combination with galactose inan amount that Al O /SO ratio of M 0 in the clinker and in anhydrite isl.2 by weight.

The initial and final setting time of mortar are determined inaccordance with the test method for setting of paste described in R5201, using a sample of which the cement/standard sand (yielded inTOYOURA) ratio is l 2 by weight. and water/cement ratio is .055 byweight and the strength of mortar is determined in accordance with thetest method described in .115 R The results are shown in H6. 1 and FIG.2. In these figures, numerals l and 2 show the cases which anhyanddecreases gradually after addition of a fixed amount of'sodiumsilicofluoride.

1t has been found also that the initial and later strength of mortarincrease with addition of hemihypressive strength of the mortar increasegradually with increase of the added amount of sodium silicofluoridedrite is not added and is added. respectively. 5 drate to the mixture ofanhydrite and sodium silicofluolt has been found from these results thatwhen galacride as compared FIG. 3 with FIGv 4. tose is used alone. thesetting time of the mortar is re- Table 3 shows the relation between thesetting time tarded and the compressive strength of mortar in the andthe compressive strength of mortar when 15 perinitial stage increasewith increase of the amount of gacent by weight of anhydrite or amixture of 13 percent lactose, but when galactose is added more than afixed It by weight of anhydrite and 2 percent by weight of amount, thecompressive strength in the initial stage is hemihydrate are added tothe clinker shown in Table lowered. 1 and the above-mentioned additivesare added to the In contrast with the above-mentioned, it has been thusobtained cement.

Table 3 Setting time Compressive strength of mortal (kg/U11 Amount ofaddition ('71) of mortal 1min.) Clinlter Anhydrite Hemihydrate Additivelnitial Final 3 hrs. 6 hrs. l day 3 days 7 days 2X days Cane sugar 85 150.3 14 23 80 124 197 310 363 445 Cane sugar 85 13 2 0.3 20 28 137 148256 288 375 513 Sodium dihydrogen 85 15 phosphate 0.3 19 24 122 135 212286 346 4-16 (based on P 85 13 do. 24 30 133 156 240 357 475 Adipic acid85 0.2 14 18 115 127 240 290 343 450 85 13 2 do. 23 102 162 263 325 38-1476 found that when anhydrite is used in combination with 30 As has beenobserved in the above. when hemihygalactose. although the setting timeis retarded more drate is added to the clinker. the initial and laterthan when galactose is used alone, strengths in the inistrength of thethus obtained cement increase. tial and later stage develop remarkably.This facts tell The relation between the setting time or thecomthatexistence ofanhydrite and galactose is essential for pressivestrength, and amount of used additives was realization of extremely highinitial and later strength. studied with respect to clinkers containing5 60 per- It has been found also that when an additive other cent ofllCaO.7A1- O .CaX- and more than 5 percent than galactose. such assodium hydrogen carbonate, of3CaO.SiO;,and further 2CaO.SiO .4CaO.A1O;,.etc. water-soluble phosphates. carboxylic acids. silicofluoand theresults were similar as the results obtained by rides. sodium silicates,ligninsulphonates, higher alcothe above-mentioned experiments. holsulfuric esters or alkylsulfonate is used, a similar re- 40 The presentinvention relates to a process for regulatsult as the above-mentioned isobtained. ing setting time of hydraulic cement which comprises Therelation between the compressive strength of clinker containing 5 60percent by weight of 1lCaO.- mortar and the added amount of anhydritewas studied 7A1 O .CaX more than 5 percent by weight of 3CaO.- withrespect to cement in which sodium fluosilicate is SiO and further2CaO.SiO solid solution and 4CaO- added 1.2 percent by weight based on Fand anhydrite .A1 O .Fe-;O anhydrite with or without hemihydrate'. isadded at various A1 O /SO weight ratio of A1 0 in at least one selectedfrom the group consisting of sugthe clinker and 80;, in anhydrite to theabovears, sodium hydrogen carbonate, water-soluble phosmentionedclinker. These results are shown in FIG. 3. phates, (e.g., orthophosphates, pyrophosphates, tri- As has been observed in the above FIG.3, it is preferpolyphosphates) carboxlyic acids (e.g., tartaric acid.able to add insoluble anhydrite to the clinker in an adipic acidetckmfsodmm silicates. ligamount that the ratio of A1 0 in the clinkerand S0,, ninsulfonates, sulfuric esters of higher alcohol and alin theanhydrite. that is, A1 O /SO ratio is between 0.7 kylsulfonates, wherebythe anhydrite is contained in an and 1.8. amount that Al O /SO weightratio of A1 0,, in the It has been found also that when an additiveother clinker and 80;, in the anhydrite is 0.7 1.8 and hemithan sodiumsilicofluoride is used,asimilar result as the hydrate is contained lessthan 5 percent by weight above-mentioned is obtained as shown by theaddition based on S0 of sodium silicofluoride. 1n the present invention,the above-mentioned addi- The relation between the compressive strengthmortives should be used preferably in an amount of 0.01 tar and theadded amount of sodium silicofluoride was 0.2 percent by weight formonosaccharide. 0.01 0.7 studied with respect to cement in which variouspercent by weight for disaccharide,0.05 1.00 percent amounts of sodiumsilicofluoride are added to the mixby weight for polysaccharide, 0.1 1.5percent by ture of 13 percent by weight of anhydrite and 2 percentweight for sodium hydrogen carbonate; 0.1 2.0 perby weight ofhemihydrate. These results are shown in cent by weight based on P 0 forwater soluble phos- FlG. 4. phates (orthophosphates. pyrophosphates andtripoly- As has been observed in the above FIG. 4, the comphosphates);0.1 5.0 percent by weight based on F for silicofluorides (Mg-, Ca-.Na-salts). 0.1 5.0 percent by weight for sodium silicates: 0.03 3.0percent by weight for sulfuric acid esters of higher alcohol andalkylsulfonates; and 0.01 1.00 percent by weight for oxyacids, e.g.,tartaric acid etc. or dicarboxylic acids, e.g., adipic acid etc.

The added amount lower than one shown in the above is not effective forthe setting time and the compressive strength of mortar or concrete andthe added amount more than one shown in the above extremely retards thesetting time and lowers the strength at the later stage as well as atthe initial stage.

As has been explained above, existence of anhydrite in clinker isresponsible for the initial and later high strength development ofcement. Addition of anhydrite with hemihydrate in clinker is effectivefor increasing the initial and later strength. The added amount ofhemihydrate is preferable to be 0.1 5.0 percent by weight based on S forcement and the added amount within a range of from 7 to 40 minutes. butalso the mortar or concrete provides good workability and the hardenedmaterial thereof develops excellent strength at the initial and thelater stages.

EXAMPLE White clay, white bauxite, quicklime. copper slag and a smallamount of gypsum as well as calcium fluoride. calcium chloride weregrounded by a shaft ball mill. 85 cm in diameter and 100 cm in length,and were mixed by means of a large-sized mixer so as to obtain clinkerhaving a composition as shown in Table 4 and the resultant mixture wasshaped by a rotating roll. 60 cm in diameter. The shaped material issintered by a small-sized rotary kiln so that free lime in the obtainedclinker was lower than 0.5 percent by weight. These results are shown inTable 4.

Table 4 Chemical composition (71) Mineral composition (71] Kind of Freeclinker SiO, A1 0,, Fe,O CaO MgO S0 Na,0 K 0 Total Time C,,A,.CaX- Q 27B 17.8 15.1 2.0 61.5 0.4 1.0 0.03 0.05 97.9 0.1 X=Cl 44 Note: Mineralcom position was determined by means of X-ray diffraction analysis.

of anhydrite is most preferable to be 0.7 1.8 at Al O S0 weight ratio ofthe amount of A1 0 in the clinker and the amount of $0 in the anhydriteand hemihydrate in the cement. When Al O /SO ratio is lower than 0.7,the hardened material of mortar or concrete is cracked and broken downand when Al O /SO ratio is more than 1.8, the compressive strength ofmortar or concrete decreases remarkably.

According to the present invention, the setting time of mortar which isprepared from the clinker comprising 5 60 percent by weight of 11CaO.7AlO CaX more than 5 percent by weight of 3CaO.SiO 2CaO.- SiO- 4CaO.Al 0.Fe O etc. is not only regulated The obtained clinker was mixed withgypsum listed in Table 5, calcium ligninsulfonate. calciumalkylsulfonate and sulfuric ester of higher alcohol, sodium hydrogencarbonate, sodium tripolyphosphate, magnesium silicofluoride,respectively, at the ratio listed by Table 6 and each thus preparedcement was tested for the setting time and compressive strength ofmortar in accordance with the test method JlS R 5201. The results aresummerized in Table 6. In Table 6, the setting time and the compressivestrength of mortar prepared from cement which was mixed alone gypsum tothe above clinker were listed to compare with the above results.

Table 5 Kind of gypsum ig.loss SiO, Al- -O;,+Fe,0 CaO MgO TotalHemihydrate 6.1 1.8 0.9 37.5 0.2 53.6 100.1 Anhydrite 1.9 1.0 40.0 0 357.2 100.4

Table 6 Setting time of mortar Amount of addition (1 by weight) (min.)Compressive strength of mortar (kg/cm) Clinker Anhy- Hemi- Additive lni-Fi- 3 hrs. 6 hrs. 1 day 3 days 7 days 28 days drite hydrate tial nal 1Surface active agent A 15 comprising mainly 17 22 118 127 204 308 354495 85 calcium lignin- (25.4) (29.8) (40.4) (65.4) (70.7) (89.9

sulfonate 0.3 A 15 Sodium hydrogen 20 25 108 136 239 2814 3114 466 85carbonate (24.4) (30.1) (49.5) (53.3) (63.2) (89.7)

0.8 A 15 Sodium tripolyphosphate 19 26 1 10 126 2511 2X9 345 453 85 0.5(25.3) (27.4) (55.6) (57.9) (72.41 in);

A 12 2 Magnesium silico- 25 30 136 166 262 310 357 491 84 fluoride(31.6) (36.5) (55.6 (60.111 (73.1) with 2.0 (based on F) Table 6-Cantin@d.

Setting time of mortar Amount of addition (1 by weight) (min)Compressive strength of mortar (kg/cm) Clinker Anhy- Hemi- Additive lni-Fi- 3 hrs. 6 hrs. day 3 days 7 days 28 days drite hydrate tial nalSurface active agent A 15 comprising mainly 23 30 130 154 246 276 343484 85 sulfuric ester (30.5) (33.6) (52.3) (57.4) (71.5) (90.4)

of higher alcohol I B 14 Magnesium silico- 26 34 125 145 224 275 324 47884 fluoride 7 (25.4) (30.4) (49.9) (56.3) (62.5) (32.6)

-.0 Surface active agent A comprising mainly 15 124 150 230 293 326 47685 calcium alkyl-sulfonate (27.6) (34.2) (50.9) (59.6) ((19.5) (88.1)

1) Values in parentheses show bending strength (kg/cm) 2) Mark showsthat the compound is solved in water kneaded together with cement Whatis claimed is: 1. A process for regulating the setting time of ahydraulic cement. which comprises the step of:

admixing the retarders of anhydrite and 0.01 0.2 weight percent of amonosaccharide. 0.01 0.7

- weight percent of a disaccharide or 0.05 1.00 weight percent of apolysaccharide with aclinker consisting essentially of 5 60 weightpercent of l l CaO.7Al O,-,.CaX wherein X represents a halogen atom. andmore than 5 weight percent of 3 C210.- SiO solid solution, 2 CaO.SiOsolid solution and 4 CaO.Al O .FeO wherein the anhydrite is present inan amount such that the weight ratio of A1 0 in the clinker to 80;. inthe anhydrite is 0.7 to 1.8.

2. A process claimed in claim 1, wherein the cement comprises anhydriteand hemihydrate.

3. A process claimed in claim 2, wherein the cement comprises less than5 percent by weight of hemihydrate.

4. A process claimed in claim 1, wherein the cement comprises 0.01 0.2percent by weight of monosaccharides.

5. A process claimed in claim 1, wherein the cement comprises 0.01 0.7percent by weight of disaccharides.

6. A process claimed in claim I, wherein the cement comprises 0.05 1.00percent by weight of polysaccharides.

7. A hydraulic cement composition. consisting essentially of:

5 60 weight percent of ll CaO.7Al O .CaX- wherein X represents a halogenatom. more than 5 weight percent of 3 CaO.SiO solid solution and further2CaO.SiO solid solution and 4CaO.Al- O;,.- i e- 0 anhydride; and 0.010.2 weight percent of a monosaccharide. 0.01 0.7 weight percent of adisaccharide or 0.05 1.0 weight percent of a polysaccharide, wherein theanhydrite is contained in an amount such that the A1 O /SO weight ratioof A1 0 in the clinker and $0 in the anhydrite is 0.7

8. A hydraulic cement composition as described in claim 7, wherein thecement composition comprises anhydrite and hemihydrate.

9. A hydraulic cement composition as described in claim 8, wherein thecement composition comprises hemihydrate less than 5 percent by weight.

1. A PROCESS FOR REGULATING THE SETTING TIME OF A HYDRAULIC CEMENT,WHICH COMPRISES THE STEP OF: ADMIXING THE RETARDERS OF ANHYDRITE AND0.01-0.2 WEIGHT PERCENT OF A MONOSACCHARIDE, 0.01-0.7 WEIGHT PERCENT OFA DISACCHARIDE OR 0.05-1.00 WEIGHT PERCENT OF A POLYSACCHARIDE WITH ACLINKER CONSISTING ESSENTIALLY OF 560 WEIGHT PERCENT OF 11CAO.7AL2O3.CAX2, WHEREIN X REPRESENTS A HALOGEN ATOM, AND MORE THAN 5WEIGHT PERCENT OF 3 CAO.SO22 SOLID SOLUTION, 2 CAO.SIO2 SOLID SOLUTIONAND 4 CAO.AL2O3.FEO3; WHEREIN THE ANHYDRITE IS PRESENT IN AN AMOUNT SUCHTHAT THE WEIGHT RATIO OF AL2O3 IN THE CLINKER TO SO3 IN THE ANHYDRITE IS0.7 TO 1.0.
 2. A process claimed in claim 1, wherein the cementcomprises anhydrite and hemihydrate.
 3. A process claimed in claim 2,wherein the cement comprises less than 5 percent by weight ofhemihydrate.
 4. A process claimed in claim 1, wherein the cementcomprises 0.01 - 0.2 percent by weight of monosaccharides.
 5. A processclaimed in claim 1, wherein the cement comprises 0.01 - 0.7 percent byweight of disaccharides.
 6. A process claimed in claim 1, wherein thecement comprises 0.05 - 1.00 percent by weight of polysaccharides.
 7. Ahydraulic cement composition, consisting essentially of: 5 - 60 weightpercent of 11 CaO.7Al2O3.CaX2, wherein X represents a halogen atom, morethan 5 weight percent of 3 CaO.SiO2 solid solution and further 2CaO.SiO2solid solution and 4CaO.Al2O3.Fe2O3; anhydride; and 0.01 - 0.2 weightpercent of a monosaccharide, 0.01 - 0.7 weight percent of a disaccharideor 0.05 - 1.0 weight percent of a polysaccharide, wherein the anhydriteis contained in an amount such that the Al2O3/SO3 weight ratio of Al2O3in the clinker and SO3 in the anhydrite is 0.7 - 1.8.
 8. A hydrauliccement composition as described in claim 7, wherein the cementcomposition comprises anhydrite and hemihydrate.
 9. A hydraulic cementcomposition as described in claim 8, wheRein the cement compositioncomprises hemihydrate less than 5 percent by weight.